Bio Bulletin 4(1): 37-42(2018) (Published by Research Trend, Website: www.biobulletin.com) ISSN NO. (Print): 2454-7913 ISSN NO. (Online): 2454-7921 Inventory of orchids in the Mount Hamiguitan Range Wildlife Sanctuary, Davao Oriental, Philippines Stela A. Dizon1, Ana P. Ocenar1 and Mark Arcebal K. Naive2* 1Department of Natural Sciences, College of Arts and Sciences, University of Southeastern Philippines, 263 Iñigo St, Obrero, Davao City, Philippines. 2Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Andres Bonifacio Ave, Iligan City, 9200 Lanao del Norte, Philippines. (Corresponding author: Mark Arcebal K. Naive) (Published by Research Trend, Website: www.biobulletin.com) (Received 09 March 2018; Accepted 22 April 2018) ABSTRACT: The orchid family is the most threatened group of plants in the Philippines, and remains to be poorly known and studied. A thorough survey was done from the base to the peak of the mountain Mount Hamiguitan Range Wildlife Sanctuary (MHRWS) to record and identify the orchid species. MHRWS harbors 45 species of orchids, 23 of them are Philippine endemic, a few may be undescribed. About 53% are epiphytes and 47% are terrestrial. The remarkable richness of orchids found in the present study highlights the importance for conservation of flora in MHRWS and other mountains and forests reserves in Mindanao. Keywords: Davao Oriental, Orchidaceae, Mindanao, Mount Hamiguitan, Philippines How to cite this article: Dizon, S.A., Ocenar, A.P. and Naïve, M.A.K. (2018). Inventory of orchids in the Mount Hamiguitan Range Wildlife Sanctuary, Davao Oriental, Philippines. Bio Bulletin, 4(1): 37-42. INTRODUCTION Harbouring more than 1,200 species with approximately 85% endemicity, Philippines is one Orchidaceae, the orchid family, is one of the of the orchid richest countries in the world richest families of seed plants. It is composed of (Cootes, 2011). five subfamilies, 880 genera and more than 25, The number is increasing as new species and 000 species worldwide (Cribb et al., 2003). It varieties continued to be found (e.g. Calaramo et elicits enthusiastic interest from botanists, but is al., 2017; Cootes et al., 2016, 2017; De Leon et also one of the most endangered plant taxa al., 2017; Naive, 2017; Naive et al., 2016, (Kreutz, 2009; Zhang et al., 2015). Orchid species 2017a&b). Many more species await scientific requires unique habitat and microhabitat, so they description, but given the increasing pace of forest are confined to particular elevations and forest destruction, many species may not be known and types (Jalal, 2013), which makes them excellent fully explored. Such threat has direct impact on the indicators of ecosystem changes (Jacquemyn et orchid flora considering that it has the highest al., 2005; Yulia, 2011; Nadkami, 1994). number of threatened species (Fernando et al., Furthermore, due to their great economic 2008). The assessment of orchid diversity and importance to floral and pharmaceutical industries, distribution is further limited by potential problems many species have been over-collected and in nomenclature that are difficult to resolve poached, and are becoming endangered (Naive et because of the lack of access to reference al., 2017a). specimens, digital imagery, and detailed collection particularly in Mindanao (Buenavista, 2017). Bio Bulletin (2018), Vol. 4(1): 37-42, Dizon, Ocenar and Naive 37 Mt. Hamiguitan Range Wildlife Sanctuary Extensive survey was carried out from July 2016-- (MHRWS) is situated in the Province of Davao October 2017 in MHRWS situated at the southern Oriental. This area is a center for endemism and a end of the Eastern Mindanao Biodiversity Corridor home to an astonishing diversity of species. It is (EMBC) La Union, San Isidro, Davao Oriental (Fig. also a protected area and was designated as a 1). MHRWS covers a 6834 hectare located World Heritage site by UNESCO (Caparas, 2012). between 6°40’01” to 6°46’60” N and 126°09’02” to MHRWS harbors 957 species of plants belonging 126°31’01” E in the southeastern part of the to 427 genera and 166 families, 723 of which are Davao Oriental Province (Amoroso & Aspiras, Angiosperms (UNESCO, 2013), and 19 orchids 2010). The reservehas an elevation range of 75 (Buenavista, 2017). Here we ground-truth the [map seems to show reserve going to the shore previous assessment. Rare species could have line = 0 m] to 1,637 meters above sea level and is been missed previously. Most orchid species are characterized by five vegetation types: agro- identified by their flowers, and few species flower ecosystem, dipterocarp forest, montane forest, throughout the year. typical mossy forest and mossy-pygmy (UNESCO, 2013). MATERIAL AND METHODS Fig. 1. Map showing the area where the study was conducted in Mt. Hamiguitan Range Wildlife Sanctuary, La Union, San Isidro, Davao Oriental, Philippines. (Google Earth, 2017). Following the established mountain trail, a transect which belongs to 24 genera in three subfamilies walk (5 m both sides) and opportunistic sampling and nine tribes (Table 1). The subfamily was done starting from the base to the peak of the Epidendroideae has the highest number of mountain. The species that could be field- species (38) followed by Orchidoideae (5) and identified were photographed to provide Cypripedioideae (2). Out of the 45 taxa recorded, records.Those species that could not be identified 38 of them are identified to species level. Some of in the field were collected. Identification was the unidentified species were not in flower, which mainly based on Valmayor (1984), Cootes (2001, prevented identification to species level. Epiphytes 2011) and Cootes & Tiong (2015). The (53%) and terrestrials (47%) were represented assessment of the species was based on DENR about equally (Table 2). Administrative Order No. 2017-11. Epiphytic orchid species are influenced by various environmental factors, such as light availability. RESULTS AND DISCUSSION Their nature in growing to their host plant is one A total of 45 taxa of identifiable Orchidaceae way of adapting to get sunlight (Tirta, 2014). species with 23 endemic species were recorded, Bio Bulletin (2018), Vol. 4(1): 37-42, Dizon, Ocenar and Naive 38 Table 1: Systematics of Orchidaceae species found in MHRWS, Davao Oriental Philippines. Subfamilies Tribe Genus Cypripedioideae Paphiopedilum Orchidoideae Cranichideae Goodyera Macodes Myrmechis Rhomboda Diurideae Corybas Cryptostylis Epidendroideae Arethuseae Coelogyne Dendrochilum Malaxideae Crepidium Dienia Liparis Cymbidieae Cymbidium Dipodium Collabieae Cephalantheropsis Plocoglottis Spathoglottis Podochileae Appendicula Ceratostylis Podochilus Trichotosia Vandeae Pomatocalpa Staurochilus Trichoglottis Dendrobieae Bulbophyllum Dendrobium Epigeneium Other factors mentioned by Dressler (1993) Administrative Order No. 2017-11). Paphiopedilum favorable to epiphytes are greater seed dispersal, ciliolare and P. adductum are listed as critically better exposure to pollinators, and avoidance of endangered (CR) and both are Philippine predators. This study harbors 24 epiphytic orchid endemics. Bulbophyllum loherianum (a Philippine species, showing that the study area provides endemic species) and Cymbidium ensifolium are suitable conditions for the survival of epiphytic categorized as Endangered (EN). Dendronium orchids. The genus Dendrobium has the highest sanderae is listed as Vulnerable (VU). number of species compared to the other genera At present, numerous orchid species in the with seven identified species, it was followed by Philippines are becoming rare in the wild and are Bulbophyllum and Dendrochilum with five and four threatened with extinction because of degradation species respectively. Most of the Dendrobium or even a total destruction of their habitats. There species recorded in this inventory were not found are still numerous undiscovered and unexplained by Buenavista (2017) namely D. guereroi, D. patterns in the distribution of wild orchids in microphyton, D. orbilobulatum, D. philippinense & MHRWS. The number of recorded species will D. sanderae. Out of the 45 species found here, almost certainly increase, with additional research only 11 were included in Buenavista (2017). and the opening up of many inaccessible Among the 45 recorded Orchidaceae species, five locations. are listed as threatened Philippine plants (DENR Bio Bulletin (2018), Vol. 4(1): 37-42, Dizon, Ocenar and Naive 39 Table 2: Orchidaceae species present in MHRWS, Davao Oriental, Philippines. Present Buenavista, Species name Habit Endemicity study 2017 1. Appendicula tembuyukenensis J.J. Terrestrial Native √ √ Wood 2. Bulbophyllum colubrimodum Ames Epiphytic Endemic √ - 3. Bulbophyllum cummingii (Lindl.) Rchb.f Epiphytic Native √ - 4. B. loherianum (Kraenzl.) Ames Epiphytic Endemic √ - 5. B. tortuosum (Blume) Lindley Epiphytic Native √ - 6. Bulbophyllum sp. Epiphytic - √ - 7. Cephalantheropsis halconensis (Ames) Terrestrial Native √ - S.S.Ying 8. C. obcordata (Lindl.) Ormerod Terrestrial Native - √ 9. Ceratostylis latipetala Ames Epiphytic Endemic - √ 10. Coelogyne marmorata Reichenbach f. Epiphytic Endemic √ - 11. Corybas sp. Terrestrial - √ - 12. Crepidium sp. 1 Terrestrial - √ - 13. Crepidium sp. 2 Terrestrial - √ - 14. Crepidium sp. 3 Terrestrial - √ - 15. Cryptostylis arachnites (Blume) Hassk Terrestrial Native √ √ 16. Cymbidium ensifolium (L.) Sw. Terrestrial Native √ - 17. Dendrobium auriculatum Ames and Epiphytic Endemic √ √ Quisumbing 18. Db. guereroi